Method of treating copper



surface of the copper,

Patented Sept. 2, 1924@ UNITED STATES PATENT OFFICE.

ROBERT J'. CUNNINGHAM AND GEORGE H. KING, OF SALT LAKE CITY, UTAH.

METHOD OF TREATING COPPER.

No Drawing.

T 0 all whom it may concern I Be it known that we, ROBERT J. CUNNING- HAM and Greece H. KING, both citizens of the United States, residing at Salt Lake City, in the county of Salt Lake, State of Utah, have invented a new and useful Method of Treating Copper, of which the following a specification.

Our present invention comprehends a novel method of treating copper, so that a harder and denser copper is obtained.

In accordance with our present invention we take commercial copper and melt it. While it is in a molten condition in the crucible. we spread sufficient common salt over it to cover the surface of the molten metal. We preferably employ what is known to the trade as c'onfectioners salt, which is a salt in a. granulated condition. The salt is preferably moistened before it is placed on the and remains until it The crucible with the molten copper is now removed from the fire and after the metal is set. but before the metal has cooled, the salt remaining on the surface is removed by skimming or pouring. The salt causes the impurities in the molten metal to rise to the surface and these impurities together with the excess salt are removed from the molten metal by the skimming or pouring. By removing the impurities in this manner, the molecules of the metal are brought closer together, the result of which is that a harder and denser copper is obtained. The copper is then reheated and poured into an iron mold to form a casting, and castings obtained in this manner are as hard as commercial cold rolled copper.

melts.

Application filed May 15, 1919.

Serial No. 297,230.

Having thus described our invention, What we claim as new and desire to secure by Let- 4 ters Patent, is

1. The method of treating copper, which consists in melting commercial copper to form a molten bath, covering the surface of the bath with salt (N aOl), after the copper has set but before it has cooled removing the excess salt and the impurities from the surface of the copper.

2. The method of treating copper, which consists in melting commercial copper to form a molten bath, covering the surface of the bath with salt (NaCl), after the copper has set but before it has cooled removing the excess salt and the impurities from the surface of the copper, reheating the copper and then letting it cool.

3. The method of treating copper, which consists in melting commercial copper to form a molten bath, covering the surface of the bath with. salt (N aCl) after the copper has set but before it has cooled removing the excess salt and the im aurities from the surface of the copper, reheating the copper and pouring it into a metal mold to form a casting.

4. The method of treating copper, which consists in subjecting commercial copper while in a molten state to the action of salt (N aCl).

ROBERT J. CUNNINGHAM. GEORGE H. KING. Witnesses:

G. D. MoVAY, F. A. NEWTON. 

